The present invention relates generally to electrical power track systems, and more particularly to an electrical power track system such as employed in track lighting systems and which employs novel track and gripper or tap elements cooperative to enable use of an elongated power track having a relatively narrow longitudinal slot allowing indirect access to electrical conductors within the track and providing enhanced appearance and improved safety over prior power track systems.
Electrical power track systems of the type employing an elongated track having a plurality of longitudinally extending conductors or bus bars carried within the track and accessible through a longitudinal slot or channel formed in the track to enable releasible engagement by a gripper or tap member carrying electrical power contacts are generally known. See, for example, U.S. Pat. Nos. 3,639,885 to Yoshiya, 3,832,503 to Crane, 4,032,208 to Berkenhoff and 4,181,388 to Donato.
A common drawback of such known track lighting systems is that the longitudinal slots or channels formed in the tracks to provide access to the internal conductors detract from a clean smooth appearance and lead to significant safety hazards due to the ease with which fingers or a conductive element, such as a screwdriver or the like, may be inserted into the open slot or channel in a manner to contact an electrical conductor within the track.
In the known power track systems, the transverse width of the access slot or channel in the track is determined by the configuration of the corresponding gripper or tap device which supports an electrical device such as a lamp or the like and carries contact means for insertion into the track to engage the power conductors carried within the track. For the most part, the prior gripper or tap devices employ a stem-like extension which is inserted into the track channel and carries a locking element and a plurality of electrical contacts which are caused to engage the track and internal conductors through a camming or rotational movement imparted to the extension or to components thereof after insertion into the track. Because the gripper, or at least the stem extension thereof, is conventionally made of an electrically non-conducting material such as plastic or the like, it must be of relatively large size in order to provide the needed strength and support for the corresponding locking element and electrical contacts. It follows that the relatively large size of the gripper extension requires a correspondingly wide width slot or channel in the track to enable insertion of the gripper extension into the slot. Such wide width slots not only provide a rather unattractive appearance, but more importantly allow the insertion of conductive elements or a child's fingers into the track and accidental contact with the electrical conductors within the track, thus presenting a significant safety hazard. Accordingly, a power track system employing a track having a relatively narrow longitudinal access slot or channel and a gripper device cooperative with the narrow slot track would enhance the visual appearance of the track and provide improved safety by inhibiting insertion of an electrically conductive instrument or a child's fingers into the slot in a manner to contact the track conductors.